For general stability of the wall system it is recommended that a continious peremeter bond beam be installed at the wall plate level and continuously reinforced with 1 Y12 bar top and bottom.
The perimeter bond beam may require tie-downs depending on wind classification, truss span & spacing and roof construction. If required see section 1
Where perimiter bond beam is used refer to detail A
note - Tie downs are not required for tiled roofs for wind classification N2 (W33N) and less.